Primary treatment for glucose intolerance is strict adherence to a diet which minimizes postprandial glucose response, and in many cases, use of medications (insulin or oral hypoglycemic agents).
Before 1921, starvation was the only recognized treatment of diabetes mellitus (DM). Since the discovery of exogenous insulin, diet has been a major focus of therapy. Recommendations for the distribution of calories from carbohydrate and fat have shifted over the last 75 years. Based on the opinions of the time, the best mix to promote metabolic control are listed in Table 1 below.
TABLE 1 History of Recommended Caloric Distribution of Persons with DM Year Carbohydrate (%) Protein (%) Fat (%) 1921 20 10 70 1950 40 20 40 1971 45 20 35 1986 50-60 12-20 30 1994 * 10-20 * *based on nutritional assessment &lt;10% saturated fat
Early recommendations limited dietary carbohydrate, because glycemic control was generally better with this type of regimen. However, over the years researchers found that low-carbohydrate, high-fat diets were associated with dyslipidemias and cardiovascular disease, because most high-fat diets consumed in industrialized countries were high in saturated fat. In 1950, the American Diabetes Association (ADA) recommended increasing the proportion of calories provided by carbohydrate to lower cardiovascular risk. While the risk for cardiovascular disease might be diminished by this strategy, research demonstrated that not all persons with DM respond favorably from the standpoint of metabolic control. In addition, the saturated fat being consumed continued to contribute to cardiovascular risk. The ADA's recommendation to restrict total fat, without regard to type of fat was challenged in the late 1980s by investigators and participants in the National Institutes of Health (NIH) Consensus Development Conference on diet and exercise in patients with type 2 DM. The recommendation of a carbohydrate-rich diet for all persons with DM also was criticized because the theory that high-carbohydrate diets improve glycemic control and insulin sensitivity was not accepted due to inconclusive evidence. The NIH Conference led to the investigation of other dietary therapies, which resulted in a radical change in the 1994 ADA nutrition recommendations. The new ADA guidelines emphasize individualization of diet strategies. The purpose is to achieve optimal glycemic and metabolic control by varying the proportion of calories provided by the macro nutrients. The proportion selected depends on goals for glycemic control, dietary preferences and response to the diet.
The American Diabetes Association (ADA) currently recommends a diet in which protein is the same as that for the general population and accounts for 10% to 20% of total calories. With protein contributing 10% to 20% of the total calories, 80% to 90% of the total calories remains to be distributed between carbohydrate and fat. The carbohydrate/fat mix is individualized according to dietary preference, treatment goals, metabolic control and the presence of other medical conditions. However, the ADA does make a recommendation for the various types of fat in the diet. Specifically, saturated fat should contribute less than 10% of total calories, and polyunsaturated fat contributing no more than 10% of total calories. The remainder of fat calories should come from monounsaturated fat and the daily intake of cholesterol should be limited to less than 300 mg. The recommendation for fiber intake is the same as for the general public with approximately 20 to 35 g/day of dietary fiber from a variety of food sources. The micro nutrient requirements of otherwise healthy persons with DM will likely be met by consuming the amounts suggested by the RDIs. The relationship of the minerals chromium and magnesium to management of DM has been the focus of much research. Individuals considered at risk for micro nutrient deficiencies should be evaluated to determine if supplementation is necessary.
Products designed as nutritionals for the person with diabetes are commercially available. These nutritional products are typically liquids or in a solid form such as nutritional bars and baked goods. The solid forms have an advantage over liquid nutritionals as the solid form does not pass through the stomach as rapidly as a liquid. Therefore, the fat content of the solid forms may be decreased as the fat is not required to slow down the passage of nutrients from the stomach. Additionally, the commercial nutritional bars incorporate various complex multi-component carbohydrate systems which are digested at different rates thereby blunting the absorption curve of carbohydrates after a meal.
Ensure.RTM. Glucerna.RTM. Nutritional Bars (Ross Products Division of Abbott Laboratories, Columbus Ohio) is a complete, balanced nutritional designed specifically for people with diabetes. Soy protein, calcium caseinate and corn protein make up 14% of total calories as protein; high fructose corn syrup, honey, microencapsulated guar gum, crisp rice, maltodextrin, soy polysaccharide, sucrose, glycerin, polydextrose and oat bran make up 61% of total calories as carbohydrate; and partially hydrogenated soy and cottonseed oils, high oleic safflower oil, canola oil and soy lecithin make up 25% of total calories as fat. Microencapsulated guar gum, soy polysaccharide, cocoa powder and oat bran contribute 4 g total dietary fiber per 1.34 oz bar. One bar provides at least 15% of the RDIs for 24 key vitamins and minerals. The product also contains the ultra trace minerals selenium, chromium and molybdenum.
Choice dm.RTM. Bar (Mead Johnson & Company, Evansville, Ind.) is a nutritional bar with fiber, antioxidants and 24 essential vitamins and minerals for people with diabetes. Calcium caseinate, soy protein isolate, whey protein concentrate, toasted soybeans, soy nuggets (soy protein isolate, rice flour, malt, salt) and peanut butter make up 17.1% of total calories as protein; lactose, fructose, sugar, dextrose, honey, maltodextrin, rice syrup, sorbitol and peanut flour make up 54.3% of total calories as carbohydrate; and palm kernel oil and canola oil make up 28.9% of total calories as fat.
Gluc-O-Bar.RTM. (Amoun Pharmaceutical Industries Co., Westmont, Ill.) is a medical food designed for the use in the dietary management of diabetes. Soy protein isolate, nonfat dry milk and peanut flour make up 23% of total calories as protein: maltodextrin, cornstarch, sorbitol, maltitol, polydextrose and crisp rice make up 70% of total calories as carbohydrate; and chocolate creme (chocolate liquor, partially hydrogenated soybean and cottonseed oil, soy bean oil) and canola oil make up 7% of total calories as fat.
U.S. Pat. No. 4,921,877 to Cashmere et al. describes a nutritionally complete liquid formula with 20 to 37% of total caloric value from a carbohydrate blend which consists of corn starch, fructose and soy polysaccharide; 40 to 60% of total caloric value from a fat blend with less than 10% of total calories derived from saturated fatty acids, up to 10% of total calories from polyunsaturated fatty acids and the balance of fat calories from monounsaturated fatty acids; 8 to 25% of total caloric value is protein; at least the minimum US RDA for vitamins and minerals; effective amounts of ultra trace minerals chromium, selenium and molybdenum; and effective amounts of carnitine, taurine and inositol for the dietary management of persons with glucose intolerance.
U.S. Pat. No. 5,545,414 to Behr et al. describes a nutritional bar which contains protein, fat and carbohydrate. A primary component of the carbohydrate system is a zein encapsulated dietary fiber known to lower serum cholesterol in humans.
U.S. Pat. No. 5,776,887 to Wibert et al. describes a nutritional composition for the dietary management of diabetics containing 1 to 50% total calories protein; 0 to 45% total calories fat, 5 to 90% total calories carbohydrate system and fiber. The carbohydrate system contains a rapidly absorbed fraction such as glucose or sucrose, a moderately absorbed fraction such as certain cooked starches or fructose and a slowly absorbed fraction such as raw corn starch.
U.S. Pat. No. 5,470,839 to Laughlin et al. describes a composition and method for providing nutrition to a diabetic patient. The composition contains a protein source, a carbohydrate source including a slowly digested high amylose starch, a fat source that includes medium chain triglycerides and has an n-6:n-3 ratio of not more than 10.
U.S. Pat. No. 4,871,557 to Linscott describes a granola bar with supplemental dietary fiber which is added to the granola bar in the form of compressed flakes.
U.S. Pat. No. 5,843,921 and 5,605,893 both to Kaufaman describe a therapeutic food composition and a method of using the therapeutic food composition to diminish fluctuations in blood sugar levels and prevent hypoglycemic episodes. The composition includes slowly absorbed complex carbohydrate, more rapidly absorbed complex carbohydrate, protein, fat and a least one sweetening agent.
The prior art describes complex multi-component carbohydrate systems which blunt the glycemic response by requiring three or more sources of carbohydrate that are absorbed at different rates. These complex multi-component carbohydrate systems possess physical characteristics which make incorporation of the multi-component carbohydrate systems into solid matrix nutritionals difficult. Additionally, these complex carbohydrate systems often have unacceptable organoleptic characteristics and are not well tolerated. For example, guar gum functions to provide viscosity in the stomach thereby slowing the release of nutrients to the small intestine. Guar gum is encapsulated to protect the soluble fiber from moisture which results in an unacceptably hard bar. However, upon chewing, the encapsulated guar gum packs in-between the teeth, swells in the mouth and catches in the throat when swallowed.
Additionally, the amounts of the multi-component carbohydrate systems required to obtain the desired effect are often not well tolerated. For example, increased levels of fermentable fiber can lead to unacceptable bloating and flatulence in many persons.
Thus, a need has developed in the art for a simple two component carbohydrate system which acts to blunt the absorption curve of carbohydrates after a meal, is well tolerated and is easily incorporated into a solid matrix nutritional. Particularly, a need has developed in the art for a good tasting nutritional bar which provides nutrients to a person with diabetes.